What to do with old tires?

[GBracing]

I have 9 sets of maxxis that were rolled with 90cc of jr tippins inside, and wiped with some of tippins outside and krug green. These tires were used one indoor race November of 2019 and have sat since and duro 60-65.. is there anything I can do to use these for indoor tires again or will they never come down in duro?

 

[jclewis]

Sand them, then Re-roll with 120cc’s of internal
Wipe and race on a track with moisture in it

 

[1fasttiller]

Sell them nice and cheap to a guy trying to fund his Jr2 racer like me

 

[CarlsonMotorsports]

^ Both good answers.